The semiconductor Integrated Circuit (IC) industry has experienced rapid growth. Technological advances in IC materials and design have produced generations of ICs where each generation has smaller feature size and more complex circuits than the previous generation. However, these advances have increased the complexity of processing and manufacturing ICs and, for these advances to be realized, similar developments in IC processing and manufacturing are needed.
Integrated circuits are typically formed onto a semiconductor wafer. Various photolithographic processes are used to form the individual components that make up the integrated circuit into the wafer. Such components include transistors, diodes, capacitors, resistors, and various interconnect features and isolation features. When the feature sizes are smaller in the advanced technologies, it is expected that the photolithography system has high resolution and accordingly short radiation wavelength. One type of photolithographic system used to form such components is an Extreme Ultra-Violet (EUV) lithographic system. An EUV lithographic system involves projecting electromagnetic radiation having a wavelength between 10 nanometers (nm) and 120 nm onto the wafer. At such a small wavelength, the electromagnetic radiation is absorbed by air and thus the process has to be performed in a vacuum to avoid such absorption.
When performing an EUV lithography process, a chuck is used to secure a wafer within a vacuum chamber for the duration of the process. One example of a type of chuck is an electrostatic chuck (E-chuck). An E-chuck includes a charged plate that uses static electrical forces to secure the semiconductor wafer to the chuck. For example, a particular portion of the wafer may be positively charged. The corresponding plate on the E-chuck is then negatively charged. These opposite charges provide an attractive force that securely holds the wafer in place during the EUV process. In some cases, the stress from the static electrical force on the wafer may cause irregularities within the wafer. To relieve the force placed on the wafer, a gas is pumped through the E-chuck to the backside of the wafer. This gas is pressurized to provide an opposing force to the static electrical force. However, the current method and the wafer structure cannot effectively reduce the pressure on the wafer. Especially, the pressure is not uniformly distributed on the wafer surface and the stress is built up.
Therefore, there is a need for a structure for a wafer and methods of making and utilizing the same to address these concerns.